This invention relates to substituted pyrrolidones and to their use in herbicidal formulations. In particular, this invention relates to substituted 1-phenyl-3-carboxyamido-pyrrolidones of the formula ##STR2## in which: R.sup.1 is a member selected from the group consisting of H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.1 -C.sub.6 alkoxy, phenyl, halo-substituted phenyl, benzyl, halo-substituted benzyl, and C.sub.1 -C.sub.6 alkyl substituted with one or more members selected from the group consisting of C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 alkylthio, penyl, hydroxyl and cyano, and
R.sup.2 is a member selected from the group consisting of H and C.sub.1 -C.sub.6 alkyl, or R.sup.1 and R.sup.2 are combined to form a member selected from the group consisting of C.sub.2 -C.sub.6 alkylene and C.sub.2 -C.sub.6 alkyleneoxyalkylene; PA1 R.sup.3 is a member selected from the group consisting of C.sub.1 -C.sub.6 alkyl and C.sub.2 -C.sub.6 alkenyl; PA1 R.sup.4 is a member selected from the group consisting of H, halogen, CH.sub.3, CF.sub.3, CF.sub.2 CHF.sub.2, CF.sub.2 CHF.sub.2, OCHF.sub.2, OCF.sub.3, SCH.sub.3, S(O)CH.sub.3, SO.sub.2 CH.sub.3, methoxyiminomethyl, methoxyimino-1-ethyl, benzyloxyiminomethyl, and benzyloxyimino-1-ethyl; PA1 n is zero or 1; PA1 X is a member selected from the group consisting of H and halogen; PA1 Y is a member selected from the group consisting of O and S; and PA1 Z is a member selected from the group consisting of O and S.
The compounds of the present invention, as will be seen from the description and test data which follows, have utility as both pre-emergence and post-emergence herbicides, against a wide range of plant species. The preferred method of application is pre-emergence, and certain compounds, notably that in which X is H, R.sup.1 is CH.sub.3, R.sup.2 is H, R.sup.3 is C.sub.2 H.sub.5, R.sup.4 is CF.sub.3, Y is O, Z is O, and n is zero, is particularly useful on sugarcane crops in view of its selectivity.
The terms "herbicide" and "herbicidal" are used herein to denote the inhibitive control or modification of undesired plant growth. Inhibitive control and modification include all deviations from natural development such as, for example, total killing, growth retardation, defoliation, desiccation, regulation, stunting, tillering, stimulation, leaf burn, and dwarfing. The term "herbicidally effective amount" is used to denote any amount which achieves such control or modification when applied to the undesired plants themselves or to the area in which these plants are growing. The term "plants" is intended to include germinate seeds, emerging seedlings and established vegetation, including both roots and above-ground portions.
It will be noted that the generic formula representing the pyrrolidones of the present invention indicates two chiral centers, one at the 3-position and the other at the 4-position of the pyrrolidone ring. Other chiral centers may exist in the various substituent groups, depending on the particular compound. The specific compounds disclosed herein each represent a mixture of enantiomers at all chiral centers present, unless otherwise indicated. Herbicidal activity for the mixture is an indication of herbicidal activity for each individual enantiomer. In certain cases, however, as is known among those skilled in the art, one enantiomer will have a greater herbicidal activity than the other enantiomer for a given chiral center.